~ 2759 ~ Journal of Pharmacognosy and Phytochemistry 2018; SP1: 2759-2762 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; SP1: 2759-2762 Rashmi Nigam Department of Plant Pathology, Janta Vedic College, Baraut, Baghpat, Uttar Pradesh, India Joginder Singh Department of Horticulture, Janta Vedic College, Baraut, Baghpat, Uttar Pradesh, India Rajendra Singh Department of Entomology, SVBPUAT, Modipuram Meerut, Uttar Pradesh, India Pradeep Saxena ICAR- Indian Grassland Fodder Research Institute (IGFRI) Jhansi, Uttar Pradesh, India Correspondence Rashmi Nigam Department of Plant Pathology, Janta Vedic College, Baraut, Baghpat, Uttar Pradesh, India Studies on the efficacy of fungal bioagents on dry shoot weight of cowpea (Vigna unguiculata (L.) Walp) Rashmi Nigam, Joginder Singh, Rajendra Singh and Pradeep Saxena Abstract The efficacy of different doses of biological control agents on dry shoot weight of cowpea ( Vigna unguiculata (L.) Walp) was studied at Indian Grassland Fodder Research Institute (IGFRI) Jhansi. A maximum increase in the dry weight of shoot was observed due to Trichoderma harzianum followed by Trichoderma viride at various doses. Both the biological agents acted more effectively at 10 to15 g dose. The study also reveals that the Trichoderma species namely Trichoderma pseudokoningii and Trichoderma koningii did not visualize any significant difference in their efficacies when compared from each other. Aspergillus flavus proved to be least effective and showed minimum dry shoot weights. Among the bioagents, Trichoderma spp. were superior than Aspergillus spp. Bavistin was also effective in increasing the dry shoot weights and was statistically at par with Trichoderma harzianum. Keywords: Biological control, Trichoderma harzianum, Aspergillus, shoot weight, cowpea, root rot Introduction Cowpea (Vigna unguiculata (L) walp is a warm season annual leguminous fodder crop mainly grown in northern and central India. Cowpea is a heat -loving, drought-tolerant crop with high protein content and lower soil fertility requirements than many other crops (Coetzee, 1995). These properties, and the presence of nodular bacteria specific to cowpea ( Bradyrhizobium spp.), make it suitable for cultivation in the hot, marginal cropping areas of Southern Africa, as well as in the cooler, higher rainfall areas. Cowpea is susceptible to a wide range of pests and pathogens that attack the crop at all stages of growth (Anilkumar et al. 1994; Emechebe and Florini, 1997; Aveling and Adandonon, 2000; Aveling et al. 2001). These include insects, bacteria, viruses and fungi. The common diseases of cowpea occurring after its sowing are comprised of complex etiology viz. pre-and post-emergence damping-off, seedling rot/blight, wilt, root rot and stem rot. Allen (1957) advocated that these diseases may be resulted due to association of one or more than one pathogenic fungi of soil and of seed borne nature, while many of the root pathogens have been characterized ecologically as root rot inhabitants (Garrett, 1970). The fungi, like Rhizoctonia solani, Macrophomina and Fusarium sp. are the most widespread and destructive plant pathogens causing root rot/dry root rot in cowpea (Davis et al. 1991). These pathogens are restricted to inject the crop either alone or as a complex there by resulting in rots before and after emergence of seedling and wilting of plants (Sumner, 1985; Singh and Gurha, 1996; Bhatnagar and Bansal, 2003; Gokulapalan et al. 2006). These disease causes substantial losses to cowpea crops (Shihata and Gad El Hak, 1989; Ushamalini et al. 1993; Abdel-Kader and Ashour, 1999; Rauf, 2000). Biological control of plant pathogens through antagonistic microorganisms is a promising alternative to the use of chemicals. The success of biological control of plant pathogens depends mainly on the ability of the introduced micro-organisms to competitively colonize the rhizosphere of the host plant, which is influenced by the availability of nutrient from the substrate or a carrier medium through which Bio-control Agent (BCA) is applied. Keeping this in mind the present the present study was aimed to investigate the effect of different doses of bioagents on fresh shoot weight of cowpea Materials and Methods The present investigations and experiments were carried out for three consecutive crop seasons at the Indian Grassland and Fodder Research Institute, Jhansi. The studies were carried out on cowpea variety IFC-901, the important forage legume which was susceptible to root rot disease.